Anaerobic digestion has been frequently used by industries and by municipalities to treat their wastes. Generally, they consist of digesters requiring extensive controls to regulate temperature, pH, alkalinity and other parameters to maintain the efficiency of the fermentation in these expensive, high-rate digesters.
Digesters are well suited for municipal effluents or industries that can regulate the quantity and quality of waste to be treated. Most industries cannot control their waste discharge and have large variations in flow, composition and concentration. These fluctuations in waste characteristics are compounded by batch discharges of recirculation tanks, washup and accidental discharges. This is specifically where the Bulk Volume Fermenter is needed.
Earthen ponds have also been extensively used for other methods of wastewater treatment such as flow equalization, holding pond, aerated lagoon, stabilization (natural) ponds and sludge ponds.
In other areas, earthen ponds or reservoirs holding potable water have used membrane liners and covers. Liners are used to reduce water leakage into the soil, and covers are used to produce a liquid-tight seal against water contamination. Some have used the same cover membranes to cover wastewater ponds, to control the odours of effluents, manures, or natural digestion, with varying degrees of success.